<template>
  <div class="app-container">
    <h2 style="text-align: center;">发布新课程</h2>

    <el-steps :active="1" process-status="wait" align-center style="margin-bottom: 40px;">
      <el-step title="填写课程基本信息"/>
      <el-step title="创建课程大纲"/>
      <el-step title="最终发布"/>
    </el-steps>
    <el-form label-width="120px">
      <el-form-item label ="课程标题">
        <el-input v-model="courseInfo.title" placeholder=" 示例：机器学习项目课：从基础到搭建项目视频课程。专业名称注意大小写"></el-input>
      </el-form-item>
      <!-- 所属分类 TODO -->
      <el-form-item label="课程分类">
      <el-select v-model="courseInfo.subjectParentId" placeholder="一级分类" @change="subjectLevelOneChange">
        <el-option  v-for="subject in subjectOneList"
                    :key="subject.id"
                    :label="subject.title"
                    :value="subject.id" />
      </el-select>
      <el-select v-model="courseInfo.subjectId" placeholder="二级分类">
        <el-option  v-for="subject in subjectTwoList"
                    :key="subject.id"
                    :label="subject.title"
                    :value="subject.id"/>
      </el-select>
      </el-form-item>
      <!-- 课程讲师 TODO -->
      <el-form-item label="课程讲师">
        <el-select v-model="courseInfo.teacherId" placeholder="课程讲师">
          <el-option  v-for="teacher in teacherList"
                      :key="teacher.id"
                      :label="teacher.name"
                      :value="teacher.id"/>
        </el-select>
      </el-form-item>
      <el-form-item label ="总课时">
        <el-input-number :min="0" v-model="courseInfo.lessonNum" controls-position="right" placeholder="请填写课程的总课时数"></el-input-number>
      </el-form-item>
      <!-- 课程简介 TODO -->
      <el-form-item label ="课程简介">
        <el-input v-model="courseInfo.description" placeholder=" "></el-input>
      </el-form-item>
      <!-- 课程封面 TODO -->
      <!-- 课程封面-->
      <el-form-item label="课程封面">

        <el-upload
          :show-file-list="false"
          :on-success="handleAvatarSuccess"
          :before-upload="beforeAvatarUpload"
          :action="BASE_API+'/eduoss/fileoss/uploadOssFile'"
          class="avatar-uploader">
          <img :src="courseInfo.cover">
        </el-upload>

      </el-form-item>
      <el-form-item label ="课程价格">
        <el-input-number :min="0" v-model="courseInfo.price" controls-position="right" placeholder="免费课程请设置为0元"></el-input-number> 元
      </el-form-item>
      <el-form-item >
        <el-button :disabled="saveBtnDisabled" type="primary" @click="saveOrUpdate">保存并下一步</el-button>
      </el-form-item>
    </el-form>
  </div>
</template>
<script>
  import course from '@/api/course'
  import subject from '@/api/subject'
  export default {
    data() {
      return {
          saveBtnDisabled:false,
          courseInfo :{
            title: '',
            subjectId: '',//二级分类id
            subjectParentId:'',//一级分类id
            teacherId: '',
            lessonNum: 0,
            description: '',
            cover:
            'https://edu-0904.oss-cn-beijing.aliyuncs.com/2022/06/12/b0d678980e76437dbac25fb96229248001.jpg',
            price: 0
          },
          teacherList:[],
          subjectOneList:[],//课程一级分类
          subjectTwoList:[],//课程二级分类
          BASE_API:process.env.VUE_APP_BASE_API, //获取dev.env.js里面地址
         /* BASE_OSS_API:process.env.VUE_APP_OSS,*/
          courseId:""
      };
    },
    created(){
        if(this.$route.params && this.$route.params.id) {
           this.courseId = this.$route.params.id;
           this.getInfo();
        }else {
          this.getAllTeacher();
          this.getOneSubjectList();
        }
    },
    methods: {
      //获取课程信息
      getInfo(){
        course.getCourseInfo(this.courseId).then(response=>{
          this.courseInfo = response.data.courseInfoVo;
           //查询所有的课程分类
           subject.getSubjects().then(response =>{
            this.subjectOneList = response.data.list;
             for(var i =0; i <this.subjectOneList.length; i++) {
                var oneSubject = this.subjectOneList[i];
                if (this.courseInfo.subjectParentId == oneSubject.id) {
                  this.subjectTwoList = oneSubject.children;
                }
             }
          })
          this.getAllTeacher();
        })
      },
      //上传成功后
      handleAvatarSuccess(res,file){
        this.courseInfo.cover = res.data.url;
      },
      //上传成功前
      beforeAvatarUpload(file) {
           const isJPG = file.type ==='image/jpeg';
           const isLt2M = file.size /1024/1024 <2;
           if (!isJPG) {
             this.$message.error("上传头像图片只能是jpg格式");
           }
           if (!isLt2M) {
            this.$message.error("上传头像图片大小不能超过2MB！");
           }
           return isJPG && isLt2M
      },
      //获取课程分类的二级分类
      subjectLevelOneChange(value) {
          for (var i =0; this.subjectOneList.length; i++) {
               var oneSubject = this.subjectOneList[i];
               if ( value === oneSubject.id) {
                 this.subjectTwoList = oneSubject.children;
                 //清空二级分类的id
                 this.courseInfo.subjectId =''
               }
          }
      },
      //获取课程分类的一级分类
      getOneSubjectList(){
        subject.getSubjects().then(response=>{
          this.subjectOneList = response.data.list;
        })
      },
      //获取讲师列表
      getAllTeacher() {
        course.getAllTeacher().then(response=>{
          this.teacherList = response.data.items;
        })
      },
      //添加课程信息
      addCourse() {
        course.addCourseInfo(this.courseInfo)
          .then(response => {
            this.$message({
              type: 'success',
              message: '添加课程信息成功!'
            });
            //alert(response.data.courseId)
            this.$router.push({path:'/course/chapter/'+response.data.courseId})
          })
      },
      //修改课程信息
      updateCourse() {
        course.updateCourseInfo(this.courseInfo)
          .then(response => {
            this.$message({
              type: 'success',
              message: '修改课程信息成功!'
            });
            //alert(response.data.courseId)
            this.$router.push({path:'/course/chapter/'+this.courseId})
          })
      },
      //保存和修改信息
      saveOrUpdate() {
        if(!this.courseInfo.id) {
          this.addCourse();
        }else {
          this.updateCourse();
        }
      }
    }
  }
</script>
<style scoped>
  .tinymce-container {
    line-height: 29px;
  }
</style>
